One hundred patients treated for breast carcinoma, fifty with left breast and fifty with right breast cancer, will be included in the current study and compared for the incidence of cardiac damage. Since the radiation dose to the heart is substantially lower in patients irradiated for right-sided tumors, comparing the incidence of findings indicating cardiac injury in the two groups will define the contribution of RT to these findings. For each patient included in the study, the incidence of cardiovascular disease will be correlated also with the volume of heart irradiated, the radiation dose delivered to that volume, the concomitant administration of cardiotoxic systemic agents, as well as to patient's age when irradiated and risk factors for developing coronary artery disease.